Sailors who race often and who are successful know their boats and how to trim the sails for those boats really well. To make good sail trim repeatable and easy for the crew to learn, many racing skippers mark their sail tracks, halyards, outhauls, Cunningham, twings, sheets, vang and traveler at points where these trimming tools can be set in various conditions. Cruisers can learn from this, too, so you can get your working sails to perform at their best.
On the headsail, have your sailmaker add black vertical lines on the foot and top of the leach so you know where to roll the sail for first, second and third reefs. Then, mark the sail tracks on the sides where the cars should be best positioned on average for each reef. On the genoa sheets, you can use colored sail thread to mark the average position for the sheet when close-hauled and sailing hard up wind; then, the crew can react to a known trim when fine-tuning the genoa’s shape.
On the mainsail, mark the halyard where it passes through a line stopper or around a cleat for three positions—eased, average and taught. Mark the mainsail outhaul and vang control lines in the same way, so when you ask a crewmember to ease the outhaul and halyard for downwind sailing, he will know just where to make the lines fast. And when you ask him to tighten the vang, he can do it visually.
For the mainsheet and traveler, you can mark the traveler’s track positions so you can move the car to windward or leeward with repeated results as you power up or depower the sail. This is particularly important on multihulls where you use the traveler almost more than the sheet to affect the main’s power.
Pinching sail trimming tricks from the race course can really help you get the most from you sails and from your boat.